Nobody quite knows what is going to happen in December when the new government regulations come into effect. Whilst I don't think it will be the end of Advantage Play by any stretch of the imagination, I think there will be quite a few casinos and books that are offering bonuses now that will be unavailable next year.
Operators have a choice of:
Signing up to the scheme
Ignoring the scheme and taking customers illegally (but as they're not based here it doesn't matter)
or Closing down to UK customers.
Tropezia Palace(whose banner sits at the top of this screen as I'm typing) have closed to UK in the short term. They may be a one-off or they may be the first of many. They may even re-open to the UK. Given the uncertainty, and the fact that UK customers will be less profitable, due either to the tax on gambling or due the costs of complying with extra regulation, it is likely that offers will be worse if they change at all.
Personally, I am now signing up to as many casinos as I can in the next five months (sportsbooks too, but I have a much longer list of casinos I haven't done. If I'm wrong and nothing changes, I haven't lost anything.